primary research questions. It is important to note that this protocol is designed to describe the core data variables in order to answer the key research questions and primary objectives outlined in the protocol. As such, the implementation of this study may include additional objectives or study components, as determined by each implementing site. Comments for the user’s consideration are provided in purple text throughout the document, as the user may need to modify methods slightly because of the local context in which this investigation will be carried out. SARS-CoV-2 and pregnancy prospective cohort study Generic protocol: Last updated 2 December 2020, version 9 1 Introduction The World Health Organization (WHO) has established an overarching working group for research institutions implementing research on coronavirus disease 2019 (COVID-19) and pregnancy known as the Pregnancy and COVID-19 Research Working Group. The working group is designed to provide a collaborative forum for scientific discussion of research on this topic, with all implementing partners being invited to join the group. In addition, WHO has established a sub-working group (SWG) that is focused on the implementation of the generic protocol. This SWG allows provision of support to sites implementing the generic protocol, and it has also been used to discuss, explain and agree on the core components of the study. We have established core criteria for study design and core variables that should be included in any local adaptation. Local adaptation of the protocol per site are discussed in relation to what is outlined in the protocol. In addition, UNDP/UNFPA/UNICEF/WHO/World Bank Special Programme of Research, Development and Research Training in Human Reproduction (HRP)/WHO holds regular individual meetings with all implementing partners that wish to be part of pooled analyses. Specifically, a small number of selected partner sites in low- and middle-income countries (LMICs) receive tailored support plans in their efforts to implement the protocol. These overarching working groups and SWGs have been in place since April/May 2020 and meet regularly to ensure continuous dialogues with implementing and collaborating partners. Further, WHO monitors any studies adaptations to design or implementation that are planned within sites. This work will be used to guide and ensure quality of implementation as well as to provide an overview of sites and their respective timelines and, additionally, ensure any protocol adaptations are within the scope of what is outlined in the generic protocol. We recognize that sites will be implementing the protocol with varied resource availabilities, and parallel initiatives of research capacity strengthening will be tailored as needed for individual sites. Through close work with WHO colleagues outside HRP, in regional and country offices, we will also ensure regular contact points. 2 Research plan The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been identified as the cause of a febrile respiratory disease officially named COVID-19 (1) that, since its appearance, has spread across the globe. COVID-19 was declared a Public Health Emergency of International Concern by the WHO DirectorGeneral on 30 January 2020. At the current rate of transmission, a majority of people worldwide, including pregnant women, will be at risk of infection and acquiring the disease. Given a paucity of knowledge regarding SARS-CoV-2 in the context of pregnancy, there is an urgent need to better understand the disease in pregnancy to improve management and outcomes in this population. The physiological, immunomodulatory and mechanical changes that occur during pregnancy can increase both a woman’s susceptibility to disease and severity for certain infections. At baseline, pregnant women are more vulnerable to respiratory distress from decreased residual lung capacity, increased oxygen consumption and higher circulating blood volume (2). It is currently unknown if pregnant women are more susceptible to infection and severe disease from SARS-CoV-2. Limited data from other coronaviruses, such as severe respiratory syndrome (SARS-CoV) and Middle East respiratory syndrome (MERS), suggest mortality rates in pregnant women range between 25-30% (3,4). SARS-CoV-2 and pregnancy prospective cohort study Generic protocol: Last updated 2 December 10 It is unknown if SARS-CoV-2 can be transmitted from the mother to the fetus in utero or at childbirth. Although four recent systematic reviews failed to report any evidence for intrauterine infection (5–8), a recent media report and evidence of neonatal IgM antibodies for SARS-CoV-2 suggest otherwise (9–11). Additionally, because nearly all reports are on women who delivered via caesarean, it is unclear if transmission can also occur during vaginal delivery. In other coronavirus outbreaks, such as SARS and MERS, there were no documented reports of in utero transmission from mother to fetus (3). The impact of SARS-CoV-2 infection on pregnancy is unclear. As the virus so recently emerged, data is lacking on outcomes associated with first or second trimester infection and risk of teratogenicity (12). One study of 8000 pregnant women with SARS-CoV-2 in the United States found that infection was associated with hospitalization,